Selvedge straightening means for flat knitting machines



1959 P. J. SCHOENSTER ETAL 2,907,195

SELVEDGE STRAIGHTENING MEANS FOR FLAT KNITTING MACHINES Filed June 27, 1955 INVENTORS v PETER J. SCHOENSTER F|G.2 v By MAX E. EBERT ATTORNEY Unitd States Patent Ofiice 2,907,195 Patented Oct. 6, 1959 SELVEDGE STRAIGHTEN'ING MEANS FOR FLAT KNITTING MACHINES Application June 27, 1955, Serial No. 518,052

9 Claims. (Cl. 66-147) This invention relates to means for, and methods of straightening the selvedges of fabrics knitted on flat knitting machines.

When knitting fabric on flat knitting machines, such as a tricot machine, the selvedges are not normally drawn off in a straight line. There is a tendency for the knitted fabric, although knitted over substantially the entire width of the machine which may be up to 168", to narrow itself and curl up in its path toward the take-01f rolls. The amount of narrowing and curling varies with the specific type of fabric being knitted and in practice, these tendencies have been left to adjust themselves at random between the knitting elements and the take-01f rolls.

The narrowing and curling tendencies of a knitted fabric during its draw oif from the knitting elements evidences an increasing slackage of tension in the fabric from the middle of the machine toward both ends thereof. This indicates that the fabric is not drawn off With an equal tension over theentire length of the machine. Such inequality in the tensioning of the fabric has a simi lar eifect on the yarn sheet so that toward the ends of the machine, the yarn shows an undesirable degree of lack of uniformity of tension, causing a fluttering of the yarn sheet toward each side of the machine.

Such variations in yarn flow has prompted the use of auxiliary means at both ends of the machine, such as spring wires to avoid snarling of yarns caused by the fluttering in the yarn flow. Also, attempts have been made to straighten the fabric selvedges by the use of inclined rollers or brushes. However, due to the narrowing tendencies of some of the tightly knitted fabrics, such expedients have been found to be inadequate to cope with the problem.

Accordingly, an object of this invention is to provide an improved method and means for drawing off the selvedges of a knitted fabric in a predetermined rectilinear path from a point adjacent the knitting elements to a point adjacent the take-01f rolls, thereby equalizing the tension of the fabric and the yarns over the entire length of the machine.

A further object of this invention is to provide an improved selvedge straightening device including means for fixedly engaging the forward end of the freshly knitted fabric at the selvedges thereof in a predetermined rectilinear path, together with means movable with the moving fabric for engaging the selvedges and guiding the same in said predetermined rectilinear path, the fixed selvedge engaging means meing automatically disengaged from the selvedges as the movable means becomes operative.

Another object of this invention is to provide an improved selvedge straightening device which may be readily attached to conventional flat knitting machines and adjustably mounted to suit the width of the fabric being knitted.

In the drawing, Fig. 1 is a sidevelevational view of a device embodying the invention, with portions cut away;

Fig. 2 is a front elevational view thereof with parts in section;

Fig. 3 is a top plan view of a portion thereof;

Fig. 4'is a partial view of a driving mechanism therefore.

Referring in detail to the drawing, 10 designates a device embodying the invention. The same comprises an elongated, flat bracket member 11 having mounting portions 12 extending from the ends thereof, the portions 12 being formed with elongated slots 13 for adjustably mounting the device on a knitting machine between the knitting elements and take-off rolls, as hereinafter described. The member 11 is beveled along one edge 14 thereof and a longitudinal groove 15 is formed in said member adjacent the beveled edge. A series of longitudinally disposed, closely spaced openings 16 extend from the bottom of groove 15 to the underside of member 11, for the purpose hereinafter appearing.

A second elongated bracket 17 is hingedly mounted on bracket 11. Bracket 17 is of inverted U shaped cross section with opposed walls 18 which have pairs of opposed lugs 19 depending from the opposite ends thereof. Pulleys 20 are mounted for free rotation on shafts 21 fixed in lugs 19. A flexible belt 22 of fabric reinforced rubber or the like, interconnects pulleys 20 and a series of longitudinally disposed, closely spaced pins 23 are fixed in said belt with their sharp ends 24 projecting outwardly of the belt and in alignment with groove 15.

The bracket 17 also includes a pair of downwardly extending angular arms 25 projecting outwardly of one wall 18, the lower ends of the arms being pivotally mounted in ears 26 extending horizontally from the upper ends of members 27 upstanding from bracket member 11. The top wall 18a of bracket 17 is curved downwardly at the rear end thereof to form a guard 28 for the rear pulley 20.

A lug 29 extending downwardly from inner wall 18 is formed with a recess 43 for receiving the end of a lock pin 30 which is slidably mounted in member 27.

On the underside of bracket member 11 adjacent the front end thereof, a pair of downwardly extending cars 31 have pivotally mounted thereon a lever arm 32 which is spring loaded as at 33 to bias said arm in a clockwise direction looking at Fig. 2. The arm 32 includes at the free end thereof a cross arm 34 having fixed therein upstanding pins 35 having sharpened ends 36 which are respectively aligned with the openings 16 extending from groove 15 in member 11.

The bracket member 11 is formed with a through slot 37 through which projects an abutment member 38 fixed at the upper end thereof to lub 29; the lower end of abutment member 38 being adapted to engage arm 32 to move the pins 35 out of openings 16.

In using the device 10 in a flat knitting machine for straightening each selvedge of the knitted fabric, said machine having needles K and sinkers S, as well as the usual take-01f rolls 39, 40; one of said devices is located on each side of the machine, the slots 13 in mounting portions 12 being used to adjust the position of the devices on the machine frame to bring fabric F being knitted by the machine.

Initially, the bracket 17 is swung to a position taking the pins 23 out of groove 15, thus moving the abutment member 38 out of engagement with arm 32. Thus, the pins 35 on cross arm 34 are biased by spring 33 into openings 16 in groove 15, the ends 36 of said pins 35 projecting slightly above the upper surface of the bracket member 11 at the groove 15. The forward end of the knitted fabric F has the opposite selvedges 41 manually impaled on pin ends 36, thus setting the opposite selvedges in a predetermined rectilinear path as determined by the pins 35.

As the fabric F is being knitted, bracket 17 is swung in a direction bringing the pins 23 on belt 22 into the groove in bracket member 11, the sharpened ends 24 of said-pins passing into selvedges 41 of fabric F. At

the same time, abutment member 38 on bracket 17 en gages lever arm 32 moving the same downwardly to withdraw the pins 35 from the selved'ges. Thus, the selvedges 41 are transferred to pins 23 which also retain said selvedges in a predetermined rectilinear path substan'tially coincident with the path determined by pins 35. Furthermore, as fabric F moves toward the take-off rolls 39, 40, the pins 23 gripping selvedges 41 move forwardly with said selvedges, rotating belt 22 about pulleys 2b.

The selvedges 41 of fabric F are disengaged from pins 23 at a point adjacent the take-off roll 39 since the fabric moves downwardly and about said roll, the rear edge of a cut-out portion of bracket member 11 being beveled as at 42 providing for smooth movement of the fabric. The bracket 17 may be retained in its operative position by means of lock pin which is pushed forwardly into a recess 43 in lug 29; the lock pin being withdrawn to permit movement of bracket 17 to its inoperative position.

While the belt 22 is shown as freely movable by virtue of the engagement of pins 23 thereon with the moving fabric F; said belt 22 may be positively moved by means of friction wheels 44, 45 which are rotated by gears 46, 47 connected to the drive of the knitting machine, not shown, thus coordinating the movement of belt 22 with the rotation of the take-off rolls 39, 40.

In the event of stoppage of the knitting machine for adjustment or the like, the lock pin 30 is retracted to allow the bracket 17 to be swung into inoperative position. As pins 23 are drawn from their-gripping relation to selvedges 41, pins on arm 34 are being urged into gripping relation with said selvedges whereby to retain said selvedges at all times in the determined rectilinear path between the knitting elements and the take-off rolls of the knitting machine. Thus the fabric F cannot curl or narrow and the difficulties previously encountered are avoided.

The tautness of fabric F between the knitting elements and the take-off rolls is sufficient to hold the selvedges 41 for impalement by pins 35 on arm 34 as the same is spring biased in an upward direction. It is understood that the belt 22 and supporting means therefor may be arranged so that the upper run of the belt has its pins engage the selvedges 41 of fabric F.

With the device of the instant invention, the tension of the yarn is equalized over the entire width of the machine and the tension is also equalized over the entire width of the fabric being knitted, thus allowing the fabric to be pulled off at the take-off rolls with uniform tension throughout the width thereof. It has been found that with such device, quality of the knitted fabric is substantially improved and efiiciency of the knitting machines, operating at high speeds, is increased.

As various changes may be made in the embodiment of the invention herein shown without departing from the spirit thereof, it is understood that all matter herein shown or described shall be deemed illustrative and not by way of limitation except as indicated in the appended claims.

Having thus disclosed our invention, we claim as new and desire to protect by Letters Patent:

1. The method of straightening a knitted fabric selvedge comprising initially engaging the stationary, forward end of freshly knitted fabric along a selvedge thereof at closely spaced intervals with means adjacent the knitting elements forming said fabric, thereafter moving and engaging the fabric with means movable in arectilinear path and gri ping said selvedge at closely spaced intervals while simultaneously disengaging said selvedge from said initial engaging means, and disengaging said selvedge from said movable engaging means adjacent a take-off roll for said fabric.

2. A device for straightening knitted fabric selvedges comprising a bracket, said bracket being formed on one surface thereof with a longitudinal groove, an endless belt mounted for rotation on said bracket in a path aligned with the groove therein, and a plurality of longitudinally disposed, closely spaced pins fixed to said belt and projecting outwardly thereof, the ends of said pins being received in the groove of said bracket as said belt is rotated.

3. A device as in claim 2 and including means for hingedly mounting said belt relative to said bracket for moving the pins toward and away from the groove in said bracket.

4. A device as in claim 3 and further including a member pivotally mounted on an opposite surface of said bracket, said member having a plurality of upstanding pins fixed thereon in longitudinally disposed, closely spaced intervals, the grooved portion of said bracket being formed with spaced openings extending to said opposite surface thereof for respectively receiving the upper portions of said last mentioned pins, spring means for biasing said member to move said last mentioned pins into said openings with the upper ends of said pins projecting above the one surface of said bracket, and abutment means on said hinged mounting means engageable with said pivoted member upon hinged movement of said mounting means in a direction to bring said first mentioned pins into the groove of said bracket and simultaneously moving said pivoted member in a direction to depress the upper ends of said second mentioned pins below the one surface of said bracket as the outer ends of said first mentioned pins move into the groove of said bracket.

5. A device for straightening a selvedge of a knitted fabric moving from the knitting elements to the take-off roll of a knitting machine comprising a base, a member mounted on said base for movement toward and away from said base, said member including a plurality of longitudinal disposed, closely spaced members extending in a predetermined rectilinear path from said knitting elements toward said take-off roll for engaging successive and closely spaced portions of the fabric selvedge and retaining said engaged selvedge portions in said predetermined rectilinear path.

6. A device as in claim 5 and further including means for movably mounting said first mentioned member relative to said base whereby movement of said member in one direction will be operative to disengage the fabric selvedge from said engaging members, means on said base movable in said predetermined rectinlinear path including a plurality of longitudinally disposed, closely spaced members for engaging successive and closely spaced portions of the fabric selvedge, means for mounting said last mentioned means for movement between inoperative and operative positions thereof, and means on said mounting means engageable with the movable mounting means of said first member for automatically moving said first mentioned member in said one direction and disengaging the fabric selvedge from said first mentioned engaging members in response to movement of said means on said base to an operative position wherein said second mentioned engaging members engage the fabric selvedge simultaneously as the first mentioned gripping members disengage said fabric selvedge.

7. For use in a flat knitting machine, having a take-off roll, a device for straightening the selvedge of knitted fabric comprising means for fixedly engaging a longitudinal portion of the fabric selvedge adjacent the knitting elements of said machine and retaining said engaged selvedge portion in a predetermined rectilinear path extending from said knitting elements toward the take-off roll of said machine, second means for engaging longitudinal portions of the fabric selvedge adjacent the knitting elements of said machine, means for moving said second means in said predetermined rectilinear path conjointly with the movement of said fabric toward the take-off roll, and means automatically responsive to the operation of said second means for rendering said first mentioned means inoperative.

8. A device as in claim 7 and further including means.

for automatically disengaging the engaging means of said second means from said fabric selvedge at the end of said predetermined rectlinear path adjacent said take-01f roll.

9. A device for straightening the selvedge of a knitted fabric moving from the knitting elements to the take-off roll of a knitting machine, comprising an elongated base member, an endless belt mounted for rotation on said base in a path extending from a point adjacent said knitting elements to said take-01f roll, a plurality of longitudinally spaced pins fixed to said belt and projecting outwardly thereof, and groove means on said base for guiding the pins on the lower run of said belt in said 5 path.

References Cited in the file of this patent I UNITED STATES PATENTS 355,818 Harling Jan. 11, 1887 10 2,603,245 Hoffman July 15, 1952 FOREIGN PATENTS 721,865 Germany June 20, 1942 906,609 France May 22, 1945 

